CONTENTS 



Paoe 



Preface v 



Paper 



I. Photons and Electrons 1 



Karl K. Darrow, Research Physicist, Bell Telephone Laboratories, 

 New York City 



II. Measurement of X-rays and Radium 43 



Lauriston S. Taylor, Associate Physicist, National Bureau of 

 Standards. Washington, D.C. 



III. Ionization and Its Bearing on the Biological Effects of 



Radiation 87 



G. Failla. Physicist, Memorial Hospital, New York City 



IV. Measurement and Application of Visible and Near-visible 



Radiation 123 



F. S. Brackett, Consulting Physicist, Smithsonian Institution, 

 Washington, D.C. 



V. The Intensity of Solar Radiation as Received at the Surface 

 OF the Earth and Its Variations with Latitude, Altitude, 



THE Season OF THE Year AND THE Time OF Day 211 



Herbert H. Kimball, Research Associate, Blue Hill Meteorological 



Observatory of Harvard University, Washington, D.C. 



Irving F. Hand, Meteorologist, U.S. Weather Bureau, Washington, 



D.C. 



VI. Statistical Treatment of Biological Problems in Irradiation 227 

 Lowell J. Reed, Professor of Biostatistics, The Johns Hopkins Uni- 

 versity, Baltimore 



VII. Photochemistry * 253 



Farrington Daniels, Professor of Chemistry, University of Wisconsin, 

 Madison 



VIII. The Effect of Radiation on Proteins 303 



Janel Howell Clark, Associate Professor of Physiology, School of 

 Hygiene and PubUc Health, The Johns Hopkins University, 

 Baltimore 



IX. Radiation and the Vitamins 323 



Charles E. Bills, Research Director, Mead Johnson and Company, 

 Evansville, Indiana 



vii 



